Gas operated shoulder weapon



Nov. 2, 1948. J. w. wEcHsLER GAS OPERATED SHOULDER WEAPON Filed July 23, 1945 2 Sheets-Sheet 1 bww/wiet N. VVEEl-ELER,

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f5/@ Q .Nm Hm l JK -mlMiIT/II L m x 4 .\r Q m, ilu@ Nov. 2, 1948. J. w. wEcHsLER GAS OPERATED SHOULDER WEAPON 2 Sheets-Sheet 2 Filed July 23, 1945 l lm UmHm gwoon/vim JDSEF'H W- VVECHSLEFQ,

Patented Nov. 2, 1948 gD/STATES `(Granted under the Vact of March 3, 1883, as

lamended April 30, 1928;- 370 0. G. 757) Claims.

The invention described herein may be manufactured and used by or for the Goverment for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to rearms and more particularly to automatic military rifles. It is specifically concerned with improvements in a rifle of the type describedand illustrated in Patent No. 2,377,338, issued June 5, 1945, toJ. C. Gara-nd for Firearm.

The M1 rie is a gas-operated, clip-fed, aircool'ed, semi-automatic (self-loading) shoulder weapon.. By semi-automatic is meant capable of performing, after firing,` the functions of extracting and ejecting the empty cartridge case, cooking the hammer, and reloading preparatory to reflring. For refiring, the trigger must be released and again pulled. Similarly, the. trigger must be separately actuated for each shot.

The semi-automatic vfeature of the rifle imposes a limitation rendering such rifle inadequate for certain uses. If this limitation were removed, the field of use of the rifle would be significantly widened.

Accordingljnit yis an object ofr 4.this invention.

to provide a firearm capable of delivering uninterruptedre automatically and at a high rate so long as the trigger is.held back and` ammunition is available in the A,.magazineor clip. Another obiect is to provide a firearm which will deliver fire either semi-automatically or. completely automatically at -the will of the operator.

A further .object is toY provide a mechanism which may readily-be installedin existing rifles similar to those of Patentr2,377,338 to convert them to full-automatic weaponsselectively semiautomatically operable.

With these and other objects in Ivziew, as1wi1l hereinaftermore fully appear, reference is made to the accompanying drawings showing one embodiment of the invention. nthedrawings:

Figure l is a fragmentary right 4side `View of a rifle in accordance with theinvention with parts broken away and showingtheselectorin position for automatic-lire;`

Figure 2 is a View .similar toY Fig. lY showing certain of the parts inv alternative positions;

Figure 3 is a 4partialsectionalviewtaken on' the plane of the line 3'`-3 of-Fig. 1;

Figure 4. is a partial sectional View,` partlyin top-p1an,-takenionrthe plane of the line 4-1-4 of Fig. 1;

-Figure 5 is an exploded view in perspective of certain modified and additional Vparts to be in- `corporated in existing ries for the practice of the invention;

Figure 6 is a view similar to Fig. 2 showing the selector in position for semi-automatic re; and

Figure 7 is a sectional view taken substantially along a planeas indicated by the line 1-7 of Eig. 1.

For constructional details of parts not shown and for a complete description of the operation andv functioning of the rifle, upon which for purposes of illustration the present invention is based, reference may be had to the aforementioned Patent No. 2,377,338.

Referring more particularly to the drawings,

wherein like reference characters designate like or corresponding parts throughout the several views, 3 designates generally the receiver of such rie, lli designates generally a trigger housing roup, and i! the operating rod which is gas- L propelled rearwardly and which is spring biased forwardly by means, not shown, -conventional in the rifle. The o-perating rod Il is provided with nger hold I2 by means of which it may be manually actuated and the rear part of the operatingxrod Il is movable in a guide'groove I3 which is formed in the right hand side of the receiver 8. The operating rod il is connected to the rifle bolt le in a conventional manner and moves the bolt rearwardly, l when thel operating rod is actuated by the gas pressure, for extracting and ejecting a cartridge case, not shown, and also moves the bolt M forward, when it is spring biased forward by its operating rod spring on counter-recoil for chambering another round of ammunition. A hammer is mounted in the trigger housing group` i9 on the pivot l5, in. the conventional manner, and said hammer i5 is en gaged Yby the bolt le upon rearward movement of the bolt for moving the hammer rearwardly and downwardly to a cocked position. A trigger l'l is pivotally mounted on a pin4 I8 and has a sear I 9 pivotally connected thereto, just above the trigger pivot i E. The hammer l5 is provided with a pair of lrear claws or hooks 2e whichare engaged under the sear l, when the hammer -is moved to a cocked position by the bolt lll, as just previouslydescribed. The trigger il' is provided with a pair of laterally projecting lugs 2l, at ,the upperend thereof which, when the trigger li is ina released position, Vare disposed to ,engagethe forwardly projecting hooks or lugs 22 onhthe hammer It?. The hammer l5 is spring biased upwardly and forwardly by hammer Yspring' which -bears.against ahammer spring plunger `24, which in turn seats in a notch in the hammer E5, above its pivot I 5. The hammer spring 23 is seated in a housing 25 having a bifurcated, closed rear end which is loosely pivoted on the trigger pivot I8 and which yieldably bears against the forward part of the sear I 9, for normally holding the upper engaging portion of the scar I9 in a forward, operative position.

The sear I9 normally catches and holds the hammer I cocked after ring of the piece and before the trigger I1 can be released. When the trigger Il' is released, the lugs 2l are moved into the path of the hooks 22 and thereafter and before the trigger is fully released the sear I9 is moved out of engagement with the rear hammer hooks 20 by the rearward movement of the upper portion of the trigger I1, which bears against the sear I9, so that after the release of the trigger I1 hammer I5 s held in a cocked position only by engagement of the trigger lugs 2I with the forward hammer hooks 22.

The parts previously described, their assembly and coaction and their operation are all conventional to the rifle and have been illustrated and described merely to better illustrate one employment of the attachment, designated generally 25, and which includes a pair of angular guide brackets 21 having upwardly extending studs 28 which engage recesses 29 in the under side of the po-rtion of the receiver 8, which forms the operating rod guide I3. The guide brackets 21 are retained in place by means of their depending blades 33 which engage screws 3l, which are removably secured in a side plate of the rifle. A sear trip lever actuating slide 32 is reciprocably sup-ported by the guide brackets 21 against the under side of the receiver guide groove I3. Slide 32 at its forward end is provided with an upturned lug or detent 33 which is disposed in a recess 34 of the receiver 8, which opens into the guide groove I3, which constitutes a modification of the receiver 8 and which is provided to accommodate a portion of the attachment 26. The lug 33 extends into the forward part of the guide groove I3 and is disposed to be engaged by the forwardly facing shoulder 35 on the operating rod II, as said operating rod approaches the forward extremity of its movement for imparting a forward movement to the slide 32. The slide 32, at its opposite, rear end, is provided with an elongated looped portion 36 which is substantially wider than the body of the slide 32. The looped portion 35 projects laterally from one side wall of the slide 32 and the exposed portion of the loop 35 is engaged by a spring backed plunger 31 which,

together with its spring 38, is mounted in a recess 39 in the receiver 8, as best seen in Fig. 3. Plunger 31 by engagement with loop 35 urges slide 32 rearwardly and against the shoulder 35.

A sear trip lever, designated generally 40, is pivotally mounted, intermediate of its ends, on a pin 4I which extends through a yoke 42. Yoke 42 is provided with a stem or shank 43 which slidably engages a longitudinally disposed bore 44 in a plate of the receiver 8, as best seen in Fig. 4. The receiver 8 is also provided with a cylindrical bore or recess 45 which opens outwardly of the right side thereof, and into which the forward end of the bore 44 opens. The right side of the rifle stock 45 is provided with a recess adapted to receive a selector latch plate 41, by means of the screw fastenings 43. A selector, designated generally 49, includes a shaft 59 having an integral crank 5I at one end thereof. Shaft 55 is rotatably mounted in the bore 45 and is provided with an eccentric portion 52, adjacent the opposite end thereof, against which the forward, inner end of the stem 43 bears, as seen in Fig. 4. The crank 5I provides means for rotating the shaft 5|] 180 for moving the eccentric portion 52 from a rearward, koperative position, as seen in Fig, 4, to a forward position within the bore which will permit a forward movement of the stem 43, for a purpose which will hereinafter be described. Selector plate 41 is provided with a pair of arcuately shaped spring arms 53 having embossed angular detent portions 54. Spring arms 53 have their free ends spaced apart to form a passage 55. The arms 53 are all set outwardly with respect to an inwardly offset portion 56 of the plate 41. The passage is provided to permit insertion of the crank 5I therethrough, and said crank is adapted to be o-scillated beneath the upper or free end portions of the arms 53, through an arc of approximately 180, for displacing the eccentric 52 forwardly or rearwardly. Crank 5I is provided with a notched portion 51 which engages one of the detent portions 54 at one eX- tremity of its movement, and the other detent portion 54 at the other extremity of its 180 movement, for latching the selector 49 with its eccentric 52 in either a forward or rearward position.

Lever 45, at its upper end, is provided with a laterally projecting pintle 58 which loosely engages in the loop 36 for pivotally connecting the upper end of lever 45 to the rear end of slide 32. A sear trip bar 59is provided with a restricted shank 60 at its forward end, which extends into and reciprocally engages a guide recess 6I in a plate of the receiver 8, and which is disposed beneath the bore 44. Guide recess 6I opens rearwardly, and sear trip 59 projects rearwardly therefrom and is provided with an enlarged concave shoulder 62, at its rear end, which engages a laterally projecting lug 63 on the upper part of the sear I9. The lug 63 constitutes .a modification of the sear I9. 'Ihe sear trip bar 59, adjacent its guid-e shank 5D, is provided with a vertical opening 64 into which the lower, tapered end 65 of the lever 45 loosely extends.

From the foregoing it will be apparent that when the selector 49 is moved to its position of Figs. 1, 2, and 4, the attachment 425 will be in an operative position for converting the rifle, from a semi-automatic, to a full automatic firearm. With the parts thus disposed, the yoke 42 will be held in its rearmost position by the eccentric 52 being displaced rearwardly, as seen in Fig. 4, to provide an abutment for the forward end of the shank 43 to hold the yoke 42 in its rearward position. With the parts thus disposed, the plunger 31 is bearing against the loop 35 for urging the slide 32 rearward, and with the operating rod II out of engagement with the lug 33, the pressure of the hammer spring 23 on the detent I9 is sufiicient to urge the sear trip 59 forwardly enough so that the sear I9 can engage and latch the hammer I5 in a cocked position, when the operating rod I I and bolt I4 move to the rear after .a round has been red. As the trigger I1 has been pulled rearwardly in order to fire a round from the piece, its lugs ZI are displaced forwardly and out of the path of movement of the forward hammer hooks 22. As the operating rod and bolt I4 move forward and as the operating rod approaches the forward extremity of its movement, the slight movement of the operating rod I I which occurs after the bolt I4 has returned to battery and been locked, constitutes the movement during which the shoulder 35 of the operating rod II engages the lug-lor .detent 33 tom'oveithe slide 32a slight distanceforwa'rd. -I'his forward movement of the' slide-53:2.rocks the Alever AMl clockwise from`v its position of lto lits `position o'f-Fi'g'. 2. This slight clockwis'efrotation of vlever 4i! produces a suiiicientrearward movement of. the sear trip bar 59 to rook the sear 'i 9 sufficiently on'its pivot. and against theaction of the hammer spring .23, to move-tlfie-"searV .I9 out. offerigagement with the hrear.hammer hoo'ksfii to release the hammer l5l therefrom.- As this occursA almost instantaneously-and whilethe trigger Il is still held rearwardly inthe position as seenin Fig. 1, the hammer will thus. be caused to'fall automatically to strikewthefiiringl-pin, 'not shown, to fire the round, not.'shown, 'whichiwas cha-mbered b'y the bolt Idon its forward, counter-recoilmovement to'produce a complete automatic functioningof th`e`piece.. `The entirecycle previously described will, ofcourse, be repeated by the hammer falling on-'the-ringLpin so that theirifll'e will continue to-iireautmatically until the trigger i'i isl released ortho supply vof ammunition contained in thefire'arm-isexhausted.

In order to: render 4the `attachment 26 inoperative so that thefpiece can be fired semi-automaticallyorin its conventional manner, it is only necessary to rotate the selectorcrank 5| upwardly and forwardly through an arc of 180 from its position of Figs. 1 and 2 to its position of Fig. 6. rIhiswill rotate the selector shaft 5% onehalf turnto displaoethe eccentric 52 forwardly and` outoof `engagement. with the forwardend ofgthefshankAS. Consequently,- the forwardpull exerted. on. 4vthe. slide 32 .by the "operating rod ll; inapproaching itsforwardposition, will canse the .ilever 4d to .be moved forward at vits Ypivot point to its position .of Fig. 6, thus moving the trip bar 59 forwardly sufficiently to disengage it from the sear lug 53. As a result, the neXt time that the operating rod Il is moved rearwardly, the plunger 3l will cause the slide 32 t0 move rearwardly relatively to the pintle 53, said movement being accommodated by the elongation of the opening in the loop 3B through which pintle 58 extends. Consequently, upon forward movement of the operating rod H in counter-recoil, said rod, at the extremity of its forward movement, will move slide 32 forward relatively to the pintle 58 so that no movement of the lever 40 or trip bar 59 will result and, consequently, the piece will then function in its well-known semi-automatic manner. While the invention has been described as an attachment since it is intended to be applied to the rifles ialready manufactured, it will be obvious that it can constitute an integral part of the rifles manufactured in the future, so that such ries will be selectively full automatic or semiautomatic.

Various modications and changes in the construction and arrangement of the parts forming the invention are contemplated and may obviously be resorted to, and said invention is likewise adapted for use with other types of semiautomatic firearms without departing from the spirit and scope of the invention as hereinafter defined by the appended claims.

I claim:

1. In a rifle having a, sear, the combination of an operating slide slidably mounted in the rifle and having a detent adapted to be engaged by a reciprocating part of the rifle as said part approaches its forwardmost position for moving the slide forwardly on the rie, a lever, means Von the riiie forip'ivotallymointing'thelever intermediate of lits endsmean's operativelyconnecting one end of the lever to the 'slide,;and.a `connecting krod reciprocably'inounted. on Ythe rifle, and means connecting s'aid lrod tothe opposite Lend of the lever and adapted to bear Vagainst'the rie'sear'to move the sameto an inoperative position when the slide is moved forwardly for imparting rearward movement'to the connecting rod through the lever.

. 2. 'An attachment as in claim 41, wherein the means on 'the rifle :pivotally mounting the lever includes "a 'stem slidably 'mounted lengthwise of therifle, and a selector `means for moving Vand holding the stem in van operative or inoperative position, whereby jsaid stem can be moved to and held in an inoperative'p'ositionfor preventingactuation "ofthe sear by the operatingrod -when moved forwardly.

:3. "An attachment as. in claim 1, wherein .the meansonthe rifle pivotallymounting the lever includes ia vstem 'slidably 'mounted lengthwise vof theriiieyand a selector Ameans moving and for holding the stem in'an operativecr inoperative position, wherebythe sear will -notbe 'actuated' by the 'forward movement'ofthe operating rod when said stem is in an inoperative position, said selector meansincludlng` an. eccentric portion against which the forward end fof the stem .bears andfa crank 'connected to the eccentric for-turning the eccentric t'o displace it' forwardly to'free the stem for, forward displacement'of the shaft.

4. *An automatic fire attachment "for a rifle, comprisingia pair of Vslidably mounted rods, -andfa pivotally mounted lever connectedtoithe adjacent ends of'rs'ad rods to causethe rods to m'oveinopposite directions, one of the rodshaving a" portion adapted to beengaged by. anoperatinglpart ofthe rine. to impart forward movement 'to'said rodto thereby cause rearward movement of the other rod through said lever, and said last mentioned rod, when moved rearwardly, engaging a movable rifle part for holding the same inoperative.

5. An attachment as in claim 4, a' yoke on which said lever is pivotally mounted, said yoke being reciprocally mounted for lengthwise movement relatively to the rifle, said attachment being inoperative when the yoke is in a rearward position, and selector means for displacing the yoke rearwardly to render the attachment inoperative.

6. In a gas operated semiautomatic rifle having a bolt, an operating rod which is gas propelled for moving the bolt rearwardly for extracting and ejecting a cartridge case and spring biased forwardly for chambering a new round and for locking the bolt in battery position, a hammer disposed in the path of movement of the bolt and recocked by the rearward movement thereof, a sear engaging and holding the hammer in a cocked position and a trigger having lugs disposed in the path of movement of the hammer, when the trigger is released, said lugs being movable out of the path of movement of the hammer when the trigger is retracted; an automatic attachment for the rie, comprising the combination of a lever pivotally mounted on the rifle and intermediate its ends, a slide connected to one end of the lever and having a portion disposed in the path of forward movement of a part of the operating rod and engaged and moved forward by the operating rod as it approaches the forward extremity of its movement, and a sear trip bar slidably mounted lengthwise on the riiie and connected to the opposite end of the lever and moved rearwardly by the forward movement of the slide, said sear trip bar engaging and moving the sear 'to a released position whereby the hammer is released from engagement with the sear when the sear trip bar is moved rearwardly.

7. An attachment as in claim 6, a yoke in which the lever is pivotally mounted, said yoke being mounted in the rifle for movement forwardly and rearwardly of the rifle for rendering the attachment inoperative or operative, respectively.

8. An attachment as in claim 6, and selector means including a yoke for pivotally mounting the lever, said yoke having a stem mounted in the rile for forward and rearward movement, and a manually operable forwardly and rearwardly displaceable abutment for engaging the forward end of the stern for rendering the attachment operative, when the abutment is displaced to rearwardly, and inoperative, when the abutment is displaced forwardly relatively to the riiie.

9. An attachment as in claim 6, said attachwardly for opening the bolt for extracting and 5 ejecting a cartridge case and spring biased forwardly for ohambering a new round and for locking the bolt in battery position, a trigger, a sear pivotally mounted on the trigger, a hammer disposed in the path of movement of the bolt and engaged thereby, on the rearward movement of the bolt, an-d moved to a cocked position, said hammer being engaged and held by the Sear, when moved to a cocked position, said trigger having lugs dise posed in the path of movement of the hammer, when the trigger is in a released position, and out of the path of movement of the hammer when the trigger is retracted, said trigger functioning to release the sear from the hammer, when the trigger is released, to cause the trigger lugs to engage the hammer so that the iirearm will function semi-automatically to re when the trigger is released and again pulled; the combination of a slide having an elongated slot and actuated by the forward movement of the operating rod, a yoke means slidably mounted in the riile, a lever pivoted on said yoke and having a pin extending through the elongated slot, a trip bar adapted to disengage the sear from the hammer, while the trigger is in a retracted position, to cause full automatic operation of the rearm, said trip bar having an opening, said lever having a projection within said opening, and manually operable means whereby said yoke means may be displaced forwardly of the rifle and thereby said trip bar.

JOSEPH W. WECHSLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,103,228 Swebilius et al July 14, 1914 1,308,016 Clark June 24, 1919 2,029,839 Sedgley et al- Feb. 4, 1936 2,356,727 Reising Aug. 22, 1944 2,371,012 Woodhull Mar. 16, 1945 2,377,338 Garand June 5, 1945 2,388,443 Ruger Nov. 6, 1945 

